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Malware type: Trojan
Destructive: No
Platform: Windows XP (64-bit), Windows Vista (64-bit), Windows 7 (64-bit)
In the wild: Yes

Technical Details

File size: Varies
File type: DLL
Initial samples received date: 13 Feb 2014

Arrival Details

This malware arrives via the following means:

  • Patched by other malware (TROJ_ZEKOS.B)

Other Details

This Trojan requires the following additional components to properly run:

  • %System%\{random filename}.{random extension} - downloaded by TROJ_ZEKOS.B

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)


Minimum scan engine: 9.700
First VSAPI Pattern File: 10.604.07
First VSAPI Pattern Release Date: 13 Feb 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.


Step 2

Locate the file %System%\{random name}.{random extension} with the following details:

  • Description: Distributed COM Services
  • Internal Name: rpcss.dll

If no file is found, you may get this file from backup. If backup is not available, do not proceed with further steps and contact support for further assistance.

Step 3

Terminate the process which uses rpcss.dll by doing the following:

  1. Open command prompt. Click Start>Run. Type CMD and press Enter.
  2. Type tasklist /FI "MODULES eq rpcss.dll". Take note of the PID for all listed processes.
  3. Type taskkill /pid {PID Listed 1} /pid {PID Listed 2} /pid {PID Listed n} /F
  4. Type shutdown -a to prevent the machine from shutting down.
  5. Delete the file %System%\rpcss.dll and %System%\dllcache\rpcss.dll.
  6. Rename the file found in step 2 with using rpcss.dll.

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PTCH_ZEKOS.SM. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

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Analysis By: Mark Joseph Manahan

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